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<TITLE>[Chapter 7] 7.4 Scribbling in Java 1.1</TITLE>
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<h2 CLASS=sect1><A CLASS="TITLE" NAME="JNUT2-CH-7-SECT-4">7.4 Scribbling in Java 1.1</A></h2>

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The Java 1.1 event model is quite flexible, and, as we'll
see, there are several different ways you can use it to
structure your event-handling code.
<A HREF="ch07_04.htm#JNUT2-CH-7-EX-2">Example 7.2</A>
shows the first technique.  Once again, this is our basic
<tt CLASS=literal>Scribble</tt> applet, this time using the
Java 1.1 event model.  This version of the applet
implements the <tt CLASS=literal>MouseListener</tt> and
<tt CLASS=literal>MouseMotionListener</tt> interfaces itself, and registers
itself with its own <tt CLASS=literal>addMouseListener()</tt> and
<tt CLASS=literal>addMouseMotionListener()</tt> methods.

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<h4 CLASS=example><A CLASS="TITLE" NAME="JNUT2-CH-7-EX-2">Example 7.2: Scribble: Implementing the Listener Interfaces Directly</A></h4>

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<PRE>
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
public class Scribble2 extends Applet
                      implements MouseListener,  MouseMotionListener {
  private int last_x, last_y;
  public void init() {
    // Tell this applet what MouseListener and MouseMotionListener
    // objects to notify when mouse and mouse motion events occur.
    // Since we implement the interfaces ourself, our own methods are called.
    this.addMouseListener(this);
    this.addMouseMotionListener(this);
  }
  // A method from the MouseListener interface.  Invoked when the
  // user presses a mouse button.
  public void mousePressed(MouseEvent e) {
    last_x = e.getX();
    last_y = e.getY();
  }
  // A method from the MouseMotionListener interface.  Invoked when the
  // user drags the mouse with a button pressed.
  public void mouseDragged(MouseEvent e) {
    Graphics g = this.getGraphics();
    int x = e.getX(), y = e.getY();
    g.drawLine(last_x, last_y, x, y);
    last_x = x; last_y = y;
  }
  // The other, unused methods of the MouseListener interface.
  public void mouseReleased(MouseEvent e) {;}
  public void mouseClicked(MouseEvent e) {;}
  public void mouseEntered(MouseEvent e) {;}
  public void mouseExited(MouseEvent e) {;}
  // The other method of the MouseMotionListener interface.
  public void mouseMoved(MouseEvent e) {;}
}
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